ABRAMS, M. H. A Glossary of Literary Terms. 7th Ed. Fort Worth: Harcourt Brace College Publishers, 1999.
Abrams. 1999
[p. 10] In ordinary usage “ambiguity” is applied to a fault in style; that is, the use of a vague or equivocal expression when what is wanted is precision and particularity of reference.
GREEN, Roland et al., Eds. The Princeton Encyclopedia of Poetry and Poetics. Fourth Edition. Princeton University Press, 2012.
Green 2012
Ambiguity
[p. 43] (lat. ambiguitas, from ambigere “to dispute about”, literally “to wander”)
In lit. crit. ambiguity is primarily defined as he simultaneous availability of more than one meaning or interpretation. It has been variously identified as a property of verbal structure (lexical, semantic, and syntactic), of literary forms and genres themselves, and of readerly practices. (…) An ambiguous argument was an argument that appeared to be true and untrue at the same time and was, thus, logically untrue. (…) But in a literary context, Virgil’s suggestive use of the noun ambages in Aeneid 6.99 to denote the ambiguous prophecy of the Cumaean Sybil, was noticed by Dante, Boccaccio, Chaucer and others who introduce the Lat. term directly into their vernaculars to suggest perniciously doubled meanings.